On Feb 12, 2013, at 11:17 PM, Matthew Knepley <[email protected]> wrote:

Regardless of these two, PetscSection does not belong in the vector subdirectory and most definitely not in the impls/seq directory, so even if in the end it does not become exactly an IS it more belongs in the is directory then in the vec directory

That is convincing.

...

c) I believe the claim will be, "I can always think of the output as a list of integers", however that is a very broad category, which also includes graphs, meshes, etc. Internally this looks nothing like a list of numbers, and the current queries do not just return members of this list.

a graph and mesh most definitely cannot be thought of as a list of integers since they contain information about relationships BETWEEN items. Does PetscSection contain such additional information?

Yes. PetscSection represents groups of numbers, and you can see the grouping.

What queries "do not just return members of this list" in PETSc section? (That is queries we wish to retain anyways).

For example, you can ask "how many items are in group p?". This is crucial, and the whole point of the structure. I don't see how you can recover that information from just the list of dof numbers.

Then a PetscSection is a collection of lists of integers. An IS is a single list of integers. So let's make IS be a collection of lists of integers (what was previously a PetscSection) and the current use of IS becomes a special case. Barry

Matt

Barry

...

Matt

2) matimpl.h really needs vecimpl.h?

#define __MATIMPL_H

#include <petscmat.h> #include <petsc-private/petscimpl.h> #include <petsc-private/vecimpl.h>

Doesn't seem to so I've removed the vecimpl.h and pushed

Seems there may be a few of these unneeded dependencies hanging around, I'll try to hunt them down.

Barry

-- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener

-- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener